Small volume transit-mix

ABSTRACT

Method and apparatus for the mixing and transport of small volumes of transmit-mix concrete. An improved mounting for a mobile concrete mixer is provided together with method and means for the loading of a transit mixer and the mixing of concrete.

United States Patent [1 1 Dunmire 259/177 R 259/177 R 259/177 R 2 676,003 4/1954 Oury 3,190,621 6/1965 3,279,763 10/1966 Seman....

[ SMALL VOLUME TRANSIT-MIX [7 61 Inventor: Paul E. Dunmire, 12 Ilavridge Road, 1

' USQMQQLJZZH Q JfJ 9.6.9.

[22] Filed:

1 Primary Examiner-Robert W. Jenkins I Attorney-Stanley Bialos et al.

July 9, 1971 211 App]. No.: 161,126

ABSTRACT Method and apparatus for the mixing and transport of small volumes of transit-mix concrete. An improved mounting for a mobile concrete mixer is provided together with method and means for the loading of a transit mixer and the mixing of concrete.

[56] References Cited UNITED STATES PATENTS 3 Claims, 10 Drawing Figures 1/1936 Rybeck...............................

Patented Oct. 23, 1973 J 4 Sheets-Sheet 1 INVENTOR'. PAUL E. DUNMIRE ATTORNEYS Patented Oct. 23, 1973 3,767,171

4 Sheets-Sheet 15 INVENTOR: PAUL E. DUNMIRE ATT NEYS Patented Oct. 23, 1973 4 Sheets-Sheet 4.

I N V E NTO R;

E. D UN MI RE .L U A DI BYI ATTORNEYS SMALL VOLUME TRANSIT-MIX BACKGROUND OF INVENTION In order to transport concrete from a mixing plant to an installation site there have been developed mobile units in the form of trucks carrying a rotary'driven drum in which there is carried pre-mixed concrete which is prevented from setting up by the rotary motion of the drum during transit. These units normally transport seven or more yards in the drum thereof and are adapted to cooperate with what is normally termed a batch plant wherein a relatively large volume of cement, aggregate and water is premixed for loading into the mobile units. This has proven highly advantageous in the pouring of large volumes of concrete at a distance from mixing plants. The presence of transit trucks on the streets and highways of this country is a familiar sight. Insofar as large scale construction is concerned, this approach or solution to the problem of providing plastic concrete has been highly successful. One of the limitations upon this approach to the transportation of plastic concrete is the substantial volume of the rotarydrum provided for transit. Many applications of concrete require relatively small volumes and the economics of existing systems for transit thereof militates against such applications;

The present invention is particularly directed to the ready and inexpensive delivery of small volumes of plastic concrete to the site of application thereof.

SUMMARY OF INVENTION There is provided by the present invention a transitmix system. The term transit-mix refers to the transportation of concrete prior to setting thereof. Such systems normally incorporate a plant wherein cement, sand, gravel and water are pre-mixed into plastic concrete. Such concrete is then loaded into a mobile unit normally in the form of a truck having a rotary driven drum thereon so that the concrete is steadily agitated during the period of transit. At the site of application or utilization of the plastic concrete, the drum is unloaded in a variety of different ways. As noted above, the prior art systems and mechanisms for the foregoing application have been well developed and found economically feasible except for the circumstances wherein a relatively small volume of concrete is required.

For commercial construction it is normally necessary to deliver or provide a substantial volume of concrete to the site of construction. On the other hand, for many, and possibly even the majority of applications of concrete, it is necessary to provide a relatively small volume of concrete to be poured into such as patios, walks, stepping stones, fish ponds, and the like. It is with respect to these latter applications that the present invention is directed. I

There is provided hereby a simple and relatively inexpensive manner of delivering a small volume'of premixed concrete in plastic form for utilization by a home-owner or the like in relatively small volume. The present invention is adapted for mounting upon a small pick-up or truck and provides the material advantage and advancement in the art of a substantial reduction in the cost of pre-mixed concrete at the site of installation.

applicable to utilization by lumber yards, nurseries, and

the like, such that transit-mix concrete may be dispensed or sold therefrom without the necessity of establishing or building a concrete mixing plant at the site of distribution. In particular the present invention incorporates methods and means for loading a rotary driven drum with the constituents of concrete such that initial mixing of these constituents is accomplished in the drum itself. Furthermore, the present invention provides for all elements of the system to be movable and of a sufficiently small size that no particular area of a distribution or sales unit need be set aside for the production of concrete for sale. The foregoing will become more apparent from the following description of a single preferred embodiment of the present invention.

DESCRIPTION OF FIGURES The present invention is illustrated as to a preferred embodiment thereof in the accompanying drawings, wherein:

FIG. 1 is a perspective view of the transit-mix apparatus of the present invention with portions of a mobile unit carrying same illustrated in phantom;

FIG. 2 is an end elevational view of the hydraulic fluid sump and bearing mount of the hydraulic transit unit of FIG. 1;

FIG. 3 is a sectional view taken in the plane 3--3 of FIG. 2;

FIG. 4 is a plan view of the unit illustrated in FIGS. 2 and 3;

FIG. 5 is a line diagram of the hydraulic operating and control portion of the unit of FIG. 1;

FIG. 6 is an end elevational view of the loading hopper of the present invention;

FIG. 7 is a central sectional view in the plane 7-7 of FIG. 6 showing the loading hopper of the present invention in connection with the rotary drum of the apparatus and illustrating connection of the two;

FIGS. 8 and 9 are side elevational views of the transit-mix apparatus and loading apparatus in successive positions in accordance with the improved process of the present invention; and

FIG. 10 is a perspective illustration of a modified bucket of a loader adapted for utilization in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENT Considering the present invention now in some detail with regard to a singlepreferred embodiment thereof and referring to the drawings, it will be seen in FIG. 1 that there is provided as a major portion of the present invention a unit 11 adapted to be mounted upon the bed or frame of a truck or pick-up 12. Unit 11 is primarily comprised of a rotatably mounted drum l3 having a conventional mixing and extracting screw internally thereof. Thus rotation of the drum in one direc- The apparatus hereof incorporates an improved rotary drum mounting adapted for installation upon the I illustrated nor particularly described herein.

The unit 11 may be adapted for removable mounting upon a variety of different wheeled vehicles. For example, the unit may be fitted between side walls of a pickup bed, placed upon the flatbed of a truck or trailer, or mounted on frame rails as shown in FIG. 1. Quick connect and disconnect means may be employed to secure the unit 11 to a vehicle or the like and removable attachment means may be provided for connecting the unit to a power take-off of a vehicle or to the hydraulic system of certain vehicles. Also the unit may be self-contained to include a motor so that it can be used on a vehicle or as a stationary unit. Movement of the unit into and out of position on a vehicle may, for example, be accomplished with a fork lift. It will be seen that the unit 11 is quite versatile and is adapted for use under a wide variety of different circumstances and conditions, and can be readily transported from a loading location to a location of use.

The drum 13 is mounted at the forward end thereof by means of a bearing 14 carrying an axial shaft of the drum. This forward drum mounting is accomplished by means of mounting the bearing 14 atop the rear end of an hydraulic fluid sump 17. This sump 17 is formed of a rigid metal enclosure extending laterally of the frame of the truck 12 and adapted to be mounted thereon.

The hydraulic fluid sump 17 is mounted transversely upon rails 18 that, in turn, are adapted to be secured to the frame or rear platform of the truck 12. This sump 17 is disposed immediately behind the cab 19 of the truck 12 transversely of the truck frame. The sump 17 is adapted to be substantially filled with hydraulic fluid 21 which may be vented by means of a vent pipe 22.

The rotary mounted drum 13 may have a variety of different rotary support means at the rear end thereof. For example, there is illustrated in FIG. 1 a bearing ring 26 about the drum adjacent the rear end thereof engaging rollers 27 mounted in a rear support frame 28 extending upwardly from the frame 18. It will thus be seen that in this or possibly other manners the drum 13 is mounted for rotation. I

Driven rotation of the drum is accomplished, for example, by the provision of an hydraulic motor 31 operated by an hydraulic control unit 32 from an hydraulic pump 33 detachably connected by means 34 to the transmission 36 of the truck 12. The motor 31 may also be mounted atop the sump 17, as upon a lateral extension 37 of the top of the sump. The hydraulic system is adapted to be operated by a single lever 41, preferably mounted at the rear of the unit as illustrated in FIG. 1. This lever 41 is connected by linkage 42 to the hydraulic control means 32. The hydraulic system may be connected as illustrated schematically in FIG. 5. A filter 43 connects the inlet of the pump 33 to the sump 17 with the pump outlet being connected to a first valve 44 connected to a control valve 46. The control lever 41 is operable to switch the control valve 46 between conditions of forward and reverse hydraulic fluid feed to the motor 31 and an intermediate position wherein fluid is directed back to the sump. The sump is vented by the vent pipe 22 extending upwardly from an upper portion of the sump above the level of liquid therein as indicated in FIG. 3.

In operation of the hydraulic system the control lever has three positions of stability. Thus, for example, the lever in a vertical position may set the control valve 46 to merely recirculate hydraulic fluid so that the motor 31 is not operated and the drum remains at rest. Movement of the control lever 41 forward as indicated in FIG. 5 may direct hydraulic fluid through the pump 31 in a forward direction so that the drum rotates in a clockwise direction as viewed from the rear thereof. Movement of the control lever in a reverse direction oppositely from that illustrated in FIG. 5 may reverse the application of hydraulic fluid to the pump by the valve 46 so that the pump rotates in the opposite direction to drive the drum in a counterclockwise direction as viewed from the rear thereof. A variety of different means may be provided for interconnecting the hydraulic motor 31 and drum 13 such as, for example, a belt drive, chain drive, or gear drive, and in FIG. 1 there is only schematically illustrated drive means 49.

The operation of the drum 13 is relatively conventional in that the drum contains an inner screw so that rotation of the drum in one direction moves material by means of the screw toward the inner end of the drum and rotation of the drum in the opposite direction moves material therein by means of the screw out the open end of the drum. Unloading of the drum is thus readily accomplished by moving the control lever to the position for reverse drum rotation. A funnel 51 is mounted on the rear support 28 immediately beneath the rear open end of the drum and a pivotally mounted trough 52 is disposed beneath the funnel. The trough 52 is preferably mounted at an angle so as to be inclined downwardly from the funnel and, by pivotally mounting the trough, it is possible then to direct liquid or plastic concrete ejected from the drum into a wheelbarrow, form or the like, for further transportation or use of the concrete. There may, of course, be provided extra trough section for extending the distance over which the concrete may be delivered via the trough.

The present invention furthermore provides an improved and highly advantageous manner of drum loading and concrete mixing. It is conventional in the field of transit-mix concrete to provide some type of plant for mixing concrete so that the mixed concrete may then be loaded into a mixer truck or the like for delivery. The present invention obviates the necessity of providing such a plant or mixer and employs the drum 13 of the present invention as the mixer for the concrete. Special structure is provided for loading of the drum, particularly with sand and aggregate, as described below.

Referring now to FIGS. 6 to 10 of the drawings, there will be seen to be illustrated a hopper 61 adapted for removable attachment to the unit 11 described above, as by means of a mounting bar 62 extending over the top of the drum 13 at the rear thereof and rigidly secured to the rear supports 28. The hopper 61 is shown to be comprised as a tapered trough open at the top and having a front wall 63 secured to the integral side and bottom wall 64 of the hopper. A pipe 66 may be secured about the upper rim of the hopper to reinforce same and an opening 67 is provided at the lower portion of the front wall 63 for egress of aggregate loaded into the hopper. Upon the front of the hopper there is provided means for mounting the hopper on the support rod 62 of the mobile unit.

In the illustrated embodiment of the present invention the support means or bar 62 is formed as a curved arcuate section and upon the front wall 63 of the hopper there is mounted a curved plate 68 matching the curvature of the support rod 62. A central locking or hook plate 69 depends from the outer edge of the curved plate 68 along the center thereof for the purpose of fitting over the top of the mounting bar 62. A pair of side mounting plates 71 and 72 extend radially inwardly from the curved plate 68 at a lesser distance from the front hopper wall 63 than the hook or lock plate 69 for the purpose of bearing upon the exterior surface of the mounting bar 62 when the hopper is secured thereto. Suitable bracing may be provided for the plates 69, 71 and 72 to prevent bending or deformation of the same.

With regard to the removable attachment or mounting of the hopper upon the mounting bar 62, reference is made to FIG. 7 wherein it will be seen that the hopper is moved downwardly at an angle toward the bar 62 until the plate 69 is disposed immediately above and behind the bar. The hopper is then moved parallel to the plane of the bar to slide the plate 69 down behind the bar 62 and rest the teeth or plates 71 and 72 against the rear surface of the bar.

The hopper 61 is additionally provided with a resilient protruding lip 76 beneath the front opening 67 in the hopper. As shown in FIG. 7, mounting of the hopper on the mounting bar 62 then disposes this lip 76 in extension forwardly of the mounting bar slightly into the rear opening in the mixer drum l3.

Considering now the manner of removably mounting the hopper 61 on the unit 1 1, it is noted that the hopper may be manually lifted and locked onto the mounting bar 62 as described above. Alternatively, it is preferable to provide mechanical means for removable attachment of the hopper and unit and in this respect reference is made to FIGS. 8 to 10. The hopper 61 is preferably movedinto and out of engagement with the unit 11 by means of a conventional loader 81. A conventional loader bucket 82, as illustrated in FIG. 10, is modified by the provision of upwardly extending hooks 83 on the front open end of the bucket. These hooks are adapted to cooperate with a lift bar 84 extending transversely across the rear of the hopper and secured beneath same by support members 86 as illustrated in FIGS. 6 and 7.

It will be appreciated that loaders, such as the one illustrated at 81 of FIG. 8, are quite conventional and are provided with hydraulic operating and control means for moving the bucket thereof in a variety of different ways to raise, lower and tip the bucket. The hopper 61 may be readily lifted by the loader merely by slipping the loader bucket hooks over the lifting bar 84 of the hopper and then pivoting the bucket into somewhat the position as illustrated in FIG. 8. The loader may then be moved into position for disposing the hopper adjacent the mounting bar of the unit 11 as illustrated, for example, in FIG. 7, and then lowering the hopper onto engagement with the mounting bar, as described above. Pivoting of the bucket downwardly by controls 87 on the loader 81 then terminates engagement of the hopper and loader bucket so that the hopper remains in engagement extending outwardly from the unit 11.

The mixer drum 13 in an empty condition is initially provided with the proper amount of water for mixing the volume of concrete to be delivered in a single load for one application. The hopper 61 is then mounted on the rear of the unit 11 in the manner described above. A predetermined amount of sand and gravel is then loaded into the drum which is rotated in a forward direction by appropriate positioning of the control lever 41. This loading operation is illustrated in FIG. 9

wherein the loader has been operated to substantially fill the bucket 62 thereof with sand and gravel as from a pile of mixed sand and gravel in a lumber yard, nursery or the like. The loader is moved into illustrated position and the bucket tilted to drop the aggregate into the hopper. It is noted in this respect that the flexible lip 76 extending forwardly of the hopper as it moves downwardly in the hopper into the rotating drum. A further point of note is the extension of this lip slightly into the drum so that the lip is touched lightly by the screw in the drum as the drum rotates. This then vibrates the hopper so that the aggregate, even though possibly in a moist condition, does move downwardly in the hopper and out through the opening 67 in the front thereof into the drum. A proper amount of cement is then added to the material in the drum as, for example, by opening the desired number of sacks of cement and dumping them into the loader bucket so that the cement may be readily raised up and dumped into the hopper.

After loading the drum with the constituents of the concrete to be delivered, the hopper is removed from the unit by means of the loader. In this respect it is only necessary to hook the loader bucket into the hopper and then to move the hopper upwardly and then rearwardly of the unit 11 back into the position illustrated in FIG. 8. The hopper may then be moved by the loader to a convenient location where it is set upon the ground or the like and released from the loader so that the loader may be subsequently employed for other tasks. Concrete is mixed within the drum by the rotary motion of the drum and agitation provided by the internal screw of the drum. During this mixing operation the truck 12 is driven to the site at which the concrete is to be employed.

Particular advantage attaches to the present invention in delivering small volumes of concrete to sites wherein but a small volume of concrete is required. During the pouring of concrete it may be necessary for the unit to discharge the concrete over some period of time and in the instance of large mixer trucks this is very expensive because of the high overhead thereof. In the present instance, however, the small nature of the unit makes it possible for the truck to remain at the discharge site for a period of time without incurring undue charges. At all times during which concrete is retained within the drum the drum is rotated in a direction to move the concrete inwardly thereof. At the site of discharge the truck is properly positioned and the operator then moves the control lever 41 to the discharge or reverse position. This reverses the direction of hydraulic fluid flow through the pump 31 so that the drum is then rotated in an opposite direction so that the screw means therein urges the concrete out of the rear end of the drum. The concrete leaving the drum falls into thefunnel 51 and thence-down into the inclined trough 52 for discharge into a wheelbarrow or possibly directly into concrete forms.

When the drum is entirely emptied it is washed out to prevent hardening of small bits of concrete that may remain, particularly on the back side of the screw therein. This is readily accomplished by means of water from a water tank 86 located at the rear of the unit and pumped into the drum, for example, through a hose by means of a small electric pump forming a part of this auxiliary water system. No detailed description of the drum interior is set forth herein inasmuch as same is substantially conventional.

With regard to mounting rotation of the drum 13 of the present invention, it is noted that the forward bearing mount 14 is comprised of bearing means accommodating a certain amount of lateral movement relative to the axis thereof and it is also provided with thrust bearing capabilities. The embodiment of the present invention illustrated herein provides rear rotary mounting of the drum only by means of the rollers 27 and drum ring 26. This then means that it is possible for the drum to bounce slightly on the rollers at the rear end thereof and, of course, it is possible if desired to provide means for preventing this radial motion. With regard to excessive radial motion, it is noted that the mounting bar 62 extends over the top of the drum in fairly close proximity thereto so that it is not possible for the drum to move any considerable distance upwardly even on very rough roads or the like. It is further noted that the particular location of the hydraulic fluid reservoir or sump l7 herein is highly advantageous inasmuch as the location thereof is otherwise relatively unusable on the truck frame and furthermore that the sump then provides support for the forward drum bearing 14.

There is provided by the present invention an advantageous and simplified method of mixing and moving small volumes of concrete. The average home-owner, for example, who may wish to employ or utilize some relatively small volume of concrete has heretofore been faced with the problem of high costs of delivery and standby time for large transit trucks or the necessity of mixing concrete by hand. The present invention solves these problems and provides small lumber yards, nurseries and the like, which conduct retail business with individuals such as home-owners with the capability of selling and providing transportation for small batches of concrete. The purchaser and ultimate user of concrete may merely present himself at the nursery or lumber yard and, upon payment of the requisite fee and possibly a deposit, drive away in the truck with the drum rotating on the back therein mixing the concrete he desires. It is not necessary in the retail outlet to provide any substantial amount of equipment nor to occupy any substantial amount of area therein for the capability afforded by the present invention. Any outlet having a loader for handling sand, gravel and the like, is thus provided with the capability of selling transitmix and particularly the portable nature of the loading hopper hereof and the manner of initially loading and mixing concrete in accordance with this invention precludes the necessity of employing any specific area or any substantial amount of area in the outlet for concrete dispensing or mixing.

The present invention has been described with respect to a single preferred embodiment; however, it is not intended to limit the invention to the details of description or illustration.

What is claimed is:

1. An improved transit-mix unit removably mounted upon a bed of a pickup truck comprising a frame unit having upright supports at the rear thereof attached to side frame members, a rigid closed hydraulic fluid sump mounted at the front of said frame, a concrete mixer drum, a bearing mounted at the front of said frame and rotatably earring the front of said drum, means rotatably mounting the rear of said drum on said upright supports, a hydraulic drive system connected to said sump and to said drum for rotation of the drum in forward and reverse directions of rotation to mix concrete and discharge concrete, disconnectable means securing said frame unit to said pickup truck, a hopper having an open top and an opening in a front wall thereof, removable mounting means comprising a hook member on said hopper secured to said support means and removably mounting said hopper at the rear of said drum with the hopper opening aligned with the drum opening and the hopper floor inclined downwardly toward the drum for loading of the drum.

2. The unit of claim 1 further defined by said hopper having a lip of limited flexibility extending outwardly from said hopper beneath the opening in the front hopper wall for extension into the drum to direct material into the drum from the hopper and engaging the drum to vibrate the hopper for insuring movement of material from the hopper.

3. An improved transit-mix unit removably mounted upon a bed of a pickup truck comprising a frame unit having upright supports at the rear thereof attached to side frame members, a rigid closed hydraulic fluid sump mounted at the front of said frame, a concrete mixer drum, a bearing mounted at the front of said frame and rotatably carrying the front of said drum, means rotatably mounting the rear of said drum on said upright supports, a hydraulic drive system connected to said sump and to said drum for rotation of the drum in forward and reverse directions of rotation to mix concrete and discharge concrete, disconnectable means securing said frame unit to said pickup truck, a curved mounting bar secured to said supports in extension over the rear of said drum, and an open topped hopper having a front wall with an opening at the bottom thereof and a floor slanting downward to said opening, said hopper having projections including a hook member on the front wall thereof for engaging said mounting bar to removably mount said hopper in position for loading of the drum with dry constituents of concrete. 

1. An improved transit-mix unit removably mounted upon a bed of a pickup truck comprising a frame unit having upright supports at the rear thereof attached to side frame members, a rigid closed hydraulic fluid sump mounted at the front of said frame, a concrete mixer drum, a bearing mounted at the front of said frame and rotatably carring the front of said drum, means rotatably mounting the rear of said drum on said upright supports, a hydraulic drive system connected to said sump and to said drum for rotation of the drum in forward and reverse directions of rotation to mix concrete and discharge concrete, disconnectable means securing said frame unit to said pickup truck, a hopper having an open top and an opening in a front wall thereof, removable mounting means comprising a hook member on said hopper secured to said support means and removably mounting said hopper at the rear of said drum with the hopper opening aligned with the drum opening and the hopper floor inclined downwardly toward the drum for loading of the drum.
 2. The unit of claim 1 further defined by said hopper having a lip of limited flexibility extending outwardly from said hopper beneath the opening in the front hopper wall for extension into the drum to direct material into the drum from the hopper and engaging the drum to vibrate the hopper for insuring movement of material from the hopper.
 3. An improved transit-mix unit removably mounted upon a bed of a pickup truck comprising a frame unit having upright supports at the rear thereof attached to side frame members, a rigid closed hydraulic fluid sump mounted at the front of said frame, a concrete mixer drum, a bearing mounted at the front of said frame and rotatably carrying the front of said drum, means rotatably mounting the rear of said drum on said upright supports, a hydraulic drive system connected to said sump and to said drum for rotation of the drum in forward and reverse directions of rotation to mix concrete and discharge concrete, disconnectable means securing said frame unit to said pickup truck, a curved mounting bar secured to said supports in extension over the rear of said drum, and an open topped hopper having a front wall with an opening at the bottom thereof and a floor slanting downward to said opening, said hopper having projections including a hook member on the front wall thereof for engaging said mounting bar to removably mount said hopper in position for loading of the drum with dry constituents of concrete. 